It's actually a great model, it's just that the SR-71 was designed not to necessarily stand out visually (not in terms of its shape but its paint finish, etc.). A different lighting angle might help, but personally I'd prefer a subtle specular effect and a slightly higher camera angle looking down a little on the plane so we see its wings and the specular highlight can give us a better impression of its shape. This would be a subtle way to outline the shape while maintaining the existing lighting and composition. Cool scene as-is though.
- Oshyan